| Bayannuur District | |
| Native Name: | Mongolian: Баяннуур сум |
| Native Name Lang: | mn |
| Settlement Type: | District |
| Pushpin Map: | Mongolia |
| Pushpin Label Position: | right |
| Pushpin Map Caption: | Location in Mongolia |
| Subdivision Type: | Country |
| Subdivision Name: | Mongolia |
| Subdivision Type1: | Province |
| Subdivision Name1: | Bayan-Ölgii Province |
| Area Total Km2: | 2,339.50 |
| Population As Of: | 2014 |
| Population Total: | 4794 |
| Timezone: | UTC + 7 |
| Utc Offset: | +7 |
| Coordinates: | 48.9503°N 91.1619°W |
Bayannuur (Mongolian: Баяннуур, Mongolian: rich lake) is a sum (district) of the Bayan-Ölgii Aimag (province) in Mongolia. It is located to the very east of the aimag capital Ölgii and it has a border with the Uvs Aimag. Like in Bayan-Ölgii's other sums, Bayannuur is primarily inhabited by ethnic Kazakhs.As of 2014 it had a population of 4794 people.[1]